1. Technical Field
The present invention relates to an electro-optical apparatus and an electronic apparatus.
2. Related Art
The electro-optical apparatuses thus far developed include an actively driven liquid crystal device that includes transistors that each serve as a switching element of a pixel electrode, provided for each pixel. The thus-configured liquid crystal device includes capacitance elements that temporarily retain a potential of each of the pixel electrodes on the basis of image signals provided, for example as disclosed in JP-A-2008-26719.
To manufacture the liquid crystal device, in particular the one including the capacitance element, for example, a semiconductor layer for constituting the transistor is first formed on a substrate. Then a lower electrode layer that constitutes the capacitance element is deposited, and a dielectric layer is deposited thereon. A contact hole is then formed so as to penetrate through the dielectric layer and the lower electrode layer for connection to the semiconductor layer, and upon forming an upper electrode layer so as to fill in the contact hole, the capacitance element electrically connected to the semiconductor layer can be obtained.
However, a natural oxide layer may be formed on a portion of the semiconductor layer exposed when the contact hole is formed. In this case, the natural oxide layer acts as resistance that impedes the conduction, after the contact hole is filled with the upper electrode layer so as to achieve the electrical connection.
As a remedy therefor, the exposed portion of the dielectric layer and the contact hole are subjected to a diluted hydrogen fluoride (DHF) treatment after the formation of the contact hole, to thereby remove the natural oxide layer formed on the semiconductor layer. Then upon forming the upper electrode layer which serves as the capacitance element, the electrical connection between the semiconductor layer and the capacitance element can be secured.
With the foregoing remedy, however, since the exposed portion of the dielectric layer is also subjected to the DHF treatment, the dielectric layer constituting a part of the capacitance element suffers a decline in withstand voltage.
In addition, it has been discovered by the present inventors that the aforementioned factors shorten the life span of the electro-optical apparatus. The foregoing technique has, therefore, a drawback in that the quality of displayed images may be degraded.